<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <style>
    .one+p{
        color:red;
        /* ~p选中One之后所有的P元素
        +p选中one之后的第一个P元素 */
    }
    </style>
    <!--  -->
    <!--  -->
</head>
<body>
    <div>
        <p class="one">hello world</>
        <p>hello world</p>
        <p>hello world</p>
        <p>hello world</p>
        <p>hello world</p>
        <p>hello world</p>
        <p>hello world</p>
    </div>
</body>
</html>